ENGINEERING 

STUDIES 


PART  I 


American  Stone  Arches 


By  CHARLES  EVAN  FOWLER,  M.  Am.  Soc.  C.  E. 


"Whoever  thinks  a  Faultless  piece  to  see, 

Thinks  what  ne’er  was,  nor  is,  nor  e’er  shall  be.” 

*  *  *  *  *  *  *  *  * 

"Content  if  hence  th’  unlearn’d  their  wants  may  view, 
The  learn’d  reflect  on  what  before  they  knew.” 


—Pope. 


FIRST  EDITION. 


NEW  YORK. 


THE  ENGINEERING  NEWS  PUBLISHING  CO. 

1899. 


ERRATA. 

Page  II — line  29,  for  ‘crown’  read  ‘spring.’ 

Page  13 — line  35,  correct  span  is  ‘150  feet.’ 

wmfc  _ / 


ENGINEERING 

STUDIES 


PART  I 

American  Stone  Arches 


By  CHARLES  EVAN  FOWLER,  M.  Am.  Soc.  C.  E. 


'Whoever  thinks  a  Faultless  piece  to  see, 

Thinks  what  ne’er  was,  nor  is,  nor  e’er  shall  be.” 
********* 

"Content  if  hence  th’  unlearn’d  their  wants  may  view, 
The  learn’d  reflect  on  what  before  they  knew.” 

— Pope. 


FIRST  EDITION. 


NEW  YORK. 

THE  ENGINEERING  NEWS  PUBLISHING  CO. 

1899. 


Copyright,  18!)!*,  by 


CHARLES  EVAN  FOWLER. 


THE  WISSAHICKON  ARCH,  PHILADELPHIA. 


► 


THE  bridge  in  Fairmount  Park,  Philadelphia,  over  Wissahickon  Creek 
is  a  very  handsome  structure,  having  been  built  from  the  design  of 
General  Russell  Thayer,  chief  engineer  of  The  Fairmount  Park 
Commission,  at  a  cost  of  $27,743,  including  the  removal  of  the  old  bridge. 

The  arch  is  on  a  skew  of  69  degrees  26  minutes,  which  is  taken  up  by 
arch  rings,  four  feet  wide  each.  The  span  of  each  ring  is  106  feet  6  inches, 
the  clear  span  of  the  arch  105  feet  and  the  rise  11  feet.  The  spring  of  the 
arch  is  about  six  feet  above  the  surface,  at  which  point  the  arch  ring  has  a 
depth  of  4  feet  6  inches,  while  the  depth  of  keystone  is  3  feet. 

The  roadway  25  feet  in  width  and  the  two  sidewalks  of  5  feet  width 
each  are  paved  with  asphalt. 

The  stone  of  which  the  arch  was  built  was  quarried  about  one-half  mile 
^e  site  and  is  a  dark  colored  gneiss.  The  stone  work  is  quarry- faced 
a  one-inch  chisel  draft  at  each  joint,  thus  making  a  two-inch 
joint.  This  gives  a  very  fine  appearance  to  the  work. 

|w  depth  at  the  center  is  relieved  by  the  solid  parapet,  which 
le  coping,  post  and  caps,  and  which  is  supported  on  a  cop- 
F/Aveli  proportioned  modillions. 

"symmetry  of  the  design  is  unfortunately  spoiled  by  the  character 
fie  bank  at  the  left  end,  which  is  the  more  to  be  regretted  as  the  right 
Rebutment  is  a  most  suitable  and  elegant  arrangement. 


THE  CABIN  JOHN  BRIDGE  AND  AQUEDUCT,  NEAR  WASHINGTON, 


4 


THE  WHEELING,  W.  VA.,  STONE  ARCH, 


o 


MEMORIAL  RRIDOE  AND  ARCH,  HARTFORD.  CONN 


6 


THE  EAST  BRIDGE,  ELYRIA,  OHIO. 


THE  WEST  BRIDGE,  ELYRIA,  OHIO. 


8 


SCHENLEY  PARK  ARCH.  PITTSBURG. 


9 


li'iGH  BRIDGE,  CROTON  AQUEDUCT,  NEW  YORK. 


10 


WISSAHICKON  ARCH,  PAIRMOUNT  PARK,  PHILADELPHIA. 


ENGINEERING  STUDIES. 

INTRODUCTION. 

This  collection  of  photographic  views  of  Engineering  Works 
should  be  found  valuable  alike  to  the  practicing  engineer  and  to  the 
student. 

Short  descriptions  and  criticisms  are  appended  to  point  out  the  good  and 
the  bad  features  of  the  designs,  with  the  view  of  bettering  the  character 
of  future  engineering  structures.  A  stone  arch  is  very  often  regarded  as 
a  work  of  art  so  aesthetic,  that  it'  cannot  be  injured  in  appearance  by  care¬ 
less  detailing.  Never  was  there  a  greater  mistake  than  this,  nor  one  more 
frequently  made. 

The  intention  is  to  bring  out  a  number  of  parts  forming  a  series  which 
will  include,  in  addition  to  stone  arches,  Bridge  Approaches  of  Masonry, 
Bridge  Towers  and  Portals,  Notable  Bridge  Piers,  Tunnel  Portals  and 
other  engineering  works  of  like  character. 

There  will  be  six  parts  devoted  to  stone  arches  of  several  countries, 
and  six  or  more  parts  devoted  to  miscellaneous  structures. 


AMERICAN  STONE  ARCHES. 


THE  CABIN  JOHN  ARCH. 

THE  largest  stone  arch  ever  built  was  the  one  constructed  over  the 
river  Adda  at  Trezzo,  by  order  of  the  Duke  of  Milan,  about  the  year 
1380.  It  had  a  span  of  251  feet  at  low  water,  but  it  was  destroyed 
in  1427,  and  now  only  about  24  feet  of  the  arch  ring,  near  each  haunch,  re¬ 
mains. 

The  largest  one  in  existence  at  the  present  time,  is  the  Cabin  John 
bridge  and  aqueduct  over  Rock  Creek,  at  Washington,  D.  C.  It  was  de¬ 
signed  by  Gen.  M.  C.  Meigs,  and  has  a  span  of  220  feet,  a  rise  of  57  feet, 
while  the  roadway  of  20  feet  width  is  101  feet  above  the  stream.  The 
arch  ring  is  of  granite,  six  feet  deep  at  the  crown  and  four  feet  at  the  cen¬ 
ter;  the  spandrels  are  of  sandstone,  laid  partially  with  radial  joints.  The 
splendid  architectural  effect  is  due  to  the  proportions  and  to  the  relief  af¬ 
forded  by  the  projecting  courses  at  the  roadway,  which  gives  a  cornice-like 
effect  in  entire  harmony  with  the  whole  design.  This  can  best  be  expressed 
by  quoting  from  what  Fergusson  has  to  say  in  his  “History  of  Architecture,” 
regarding  the  efforts  of  the  engineer  at  architectural  effects. 

“If  this  is  all  that  can  be  done  with  bridges,  (their  decoration  with  inap¬ 
propriate  details)  it  is  far  better  that  they  should  be  left,  like  most  of  those 
recently  built,  to  tell  their  own  tale  without  any  ornament  whatever.  A  long 
series  of  tall  arches  is  so  beautiful  an  object  in  itself  that  it  is  difficult  to 
injure  it;  but  occasionally  a  slight  moulding  at  the  impost,  a  bold  accen¬ 
tuation  of  the  arch,  and  bold  marking  of  the  roadwav  render  those  beauti¬ 
ful  which  otherwise  may  only  be  useful  in  appearance.” 

11 


5431 6 


THE  WHEELING  STONE  ARCH. 


THE  Wheeling  stone  arch  bridge  is  one  of  the  largest  stone  arches 
in  the  United  States,  having  a  span  of  159  feet.  The  intrados  is  the 
arc  of  a  circle,  with  a  rise  of  twenty-eight  feet.  The  depth  of  key¬ 
stone  is  4'  6".  Longitudinal  arched  voids  are  employed  underneath  the 
roadway. 

The  engineers  of  the  work  were  Hoge  &  White,  the  bridge  being  com¬ 
pleted  in  1893.  The  large  span  marks  the  structure  as  a  notable  piece  of 
engineering  work,  and  the  detail  of  the  parapet  is  very  pleasing  in  appear¬ 
ance,  although  very  simple  in  design.  The  coping  with  the  supporting 
corbels  is  also  very  effective.  Berea  stone  was  used  for  most  of  the  work, 
which  amounted  to  about  9,000  yards,  there  being  6,000  yards  of  dimen¬ 
sion  stone.  The  cost  of  the  bridge  was  $130,000. 

The  meeting  of  two  straight  grades  at  the  center  of  the  span  is  hardly 
the  best  solution  possible  for  giving  increased  waterway,  although  plenty  of 
precedent  can  be  found  for  such  an  outline.  A  much  more  pleasing  method 
would  have  been  to  use  a  parabolic  curve  for  the  longitudinal  profile  of  the 
roadway  and  coping. 

Had  the  offset  in  the  retaining  wall  been  made  at  the  springing  of  the 
arch,  as  a  division  between  the  spandrel  and  retaining  walls,  it  would  have 
been  more  logical  and  the  effectiveness  of  the  structure  as  an  architectural 
work  much  heightened. 


HARTFORD  MEMORIAL  BRIDGE  AND  ARCH. 


ONE  of  the  handsomest  stone  arch  bridges  in  the  United  States  is  the 
brownstone  structure  in  Buslinell  Park,  at  Hartford,  Conn.  Its 
effectiveness  is  largely  due  to  the  Memorial  Arch,  over  the  drive¬ 
way  leading  up  to  the  Capitol  building. 

The  bridge  was  constructed  originally  in  1850,  of  Portland  brownstone, 
and  at  a  cost  of  about  $15,000.  Of  the  five  arches,  each  having  a  span  of 
twenty-five  feet,  the  three  center  ones  are  semi-circular,  while  the  two  end 
ones  are  three  center,  with  radii  of  feet  and  14J4  feet.  The  original 
width  of  the  bridge  was  thirty-five  feet,  but  in  1885  it  was  rebuilt  to  match 
the  Memorial  Arch,  and  the  width  increased  to  forty-one  feet  extreme,  or 
with  a  roadway  of  twenty-eight  feet  and  two  sidewalks  of  four  feet  each. 
The  widening  was  accomplished  by  tearing  down  the  spandrel-walls  to  the 
top  of  the  arch  rings  and  supporting  the  added  width  by  elegant  stone 
brackets,  adding  much  to  the  beauty  of  the  bridge;  while  the  design  was 
made  to  harmonize  with  the  Memorial  by  a  parapet  railing  of  elegant 
design. 

The  remodeling  of  the  bridge  cost  $1 1 ,287,  while  the  cost  of  the  Soldiers’ 
Memorial  was  $60,000.  This  was  executed  in  brownstone  and  terra  cotta, 
from  the  designs  of  Mr.  Geo.  Keller,  a  prominent  Hartford  architect.  The 
two  structures,  when  considered  as  a  whole,  form  one  of  the  most  notable 
of  monumental  works. 


12 


THE  ELYRIA  ARCHES. 


HE  streams  at  Elyria,  Ohio,  have  solid  rock  banks  and  beds,  and  the 


skewbaeks  for  the  eastern  and  western  stone  arches  are  cut  in  the 


M.  solid  rock  of  the  banks.  The  situations  are  very  picturesque  and  the 
falls  below  the  western  bridge,  forty  feet  high,  add  much  to  the  view. 

The  eastern  arch  is  the  third  largest  stone  span  in  the  United  States  and 
was  constructed  from  the  plans  of  E.  C.  Kinney  in  1886;  the  span  being  15U 
feet,  the  rise  24  feet,  the  width  over  all  32  feet,  while  the  depth  of  the  arch 
ring  at  the  springing  is  4  feet  6  inches  and  at  the  keystone  3  feet  9  inches. 
In  the  view  of  this  arch,  a  beautiful  two-span  stone  bridge  on  the  Lake  Shore 
Railway  can  be  seen  in  the  background. 

The  western  arch  was  designed  by  E.  S.  Jackson  and  E.  M.  Bunee  and 
was  built  in  1894.  This  span  is  the  fifth  largest  in  the  United  States,  having 
a  span  of  112  feet,  a  rise  of  19  feet  6  inches,  a  width  across  the  arch  ring  of 
38  feet,  and  a  width  on  top  of  44  feet.  The  skewbaeks  are  from  4  to  8  feet 
above  the  bed  of  the  stream,  the  arch  ring  having  a  depth  at  the  keystone  of 
3  feet  6  inches. 

Both  arches  are  constructed  with  first-class  rock-faced  masonry,  the  stone 
being  Elyria  sandstone,  quarried  in  the  vicinity.  The  width  of  both  arches 
has  been  increased  by  projecting  corbel  courses  and  coping,  which  only  serve 
to  intensify  the  shallow  depth  at  the  center.  Had  separate  corbels  been  sub¬ 
stituted  for  the  corbel  course  on  the  large  span,  and  for  the  lower  corbel 
course  on  the  small  one,  giving  the  effect  of  dentils,  the  appearance  at  the 
center  would  have  been  much  improved.  A  stone  parapet  would  have  been 
a  still  further  improvement  in  this  respect. 

While  having  the  graceful  architectural  appearance  one  would  expect  in 
arches  of  such  bold  outline,  they  are  nevertheless  somewhat  severe  in  design. 
This  effect  has  been  lessened  somewhat  by  the  addition  of  the  consoles  on 
the  eastern  arch,  which  also  afford  retreats  on  the  sidewalks. 


THE  SCHENLEY  PARK  ARCH. 


HE  stone  arch  bridge  recently  completed  in  Schenley  Park  at  Pitts¬ 


burg  is  known  as  the  Bellefield  Bridge.  It  was  designed  by  H.  B. 


*  Rust,  Engineer  of  Schenley  Park,  and  is  one  of  the  most  elaborate 
stone  bridges  in  this  country. 

It  has  a  span  of  136  feet  7  inches  and  a  width  across  the  soffit  of  82 
feet.  The  roadway  is  60  feet  in  width,  while  the  two  sidewalks  have  a  width 
of  ten  feet  each.  The  depth  of  keystone  is  four  feet. 

The  arch  is  a  very  bold  one,  and  the  general  design  leaves  little  to  be 
desired,  while  the  balustrade  is  a  most  elegant  piece  of  work.  It  is,  how¬ 
ever,  unfortunate  that  the  abutments  and  the  spandrels  were  decorated  with 
the  paneling,  as  the  apparent  size  of  the  arch  is  very  much  reduced  by  these 
details  which  have  been  characterized  by  Fergusson  in  a  criticism  of  the 
Chester  bridge  as  a  mistaken  application. —  “by  exaggerating  his  details, 
the  bridge  has  been  dwarfed  in  exactly  the  same  manner  as  the  basilica.’’ 
*  *  “It  is  far  better  that  we  should  be  content  with  plain,  honest,  solid 

but  useful  erections,  than  that  our  buildings  should  be  adorned  on  the  mis¬ 
taken  principles  which  have  hitherto  been  supposed  to  constitute  the  Art  of 
Architecture.” 


13 


HIGH  BRIDGE,  CROTON  AQUEDUCT. 


HE  most  notable  stone  bridge  in  the  United  States,  not  on  account  of 


the  size  of  the  spans,  but  because  of  its  height,  chaste  design  and  mon- 


A  umental  character,  is  the  structure  which  carries  the  Croton  Aque¬ 
duct  over  the  Harlem  River  at  New  York  City,  from  the  mainland  to  Manhat¬ 
tan  Island.  The  erection  of  the  remarkable  Washington  Bridge,  close  to  it, 
with  its  great  steel  spans,  instead  of  detracting  from  its  appearance  as  might 
be  expected  has  only  enhanced  it. 

The  original  intention  was  to  carry  the  water  across  the  river  by  a 
siphon  pipe  line  through  a  tunnel,  and,  while  the  estimated  cost  was  much 
less  than  for  a  high  bridge,  the  uncertainties  were  so  great  as  to  cause  its 
abandonment. 

The  location  is  a  very  beautiful  one,  the  south  shore  being  an  abrupt 
bluff  of  solid  gneiss  rock,  crowned  with  trees. 

The  requirements  of  navigation  made  it  necessary  to  have  a  clear  height 
of  ioo  feet  above  the  river,  and  openings  of  80  feet  in  width.  The  top  of  the 
parapet  is  116  feet  above  high  water,  while  there  are  eight  semicircular 
arches  of  80  feet  each  over  the  river,  one  arch  of  50  feet  in  the  Manhattan  ap¬ 
proach  and  six  arches  of  50  feet  span  in  the  opposite  one. 

The  river  is  620  feet  in  width  at  ordinary  high  water,  the  distance  up 
to  the  springing  of  the  arches  being  60  feet,  or  95  feet  above  the  lowest 
foundation.  The  total  length  of  the  bridge  is  1,460  feet,  and  it  originally  car¬ 
ried  two  cast-iron  pipes,  3  feet  in  diameter,  to  convey  the  water,  their  use 
being  with  the  object  of  preventing  leakage,  which  would  eventually  injure 
the  bridge.  When  it  was  desired  to  increase  the  carrying  capacity  a  third 
pipe,  7  feet  6  inches  in  diameter,  was  added. 

The  structure  was  designed  under  John  B.  Jervis,  Chief  Engineer  of 
the  Croton  Aqueduct,  and  was  let  at  a  contract  price  of  $737,755.  It  occu¬ 
pied  five  years  in  building,  being  completed  in  1842. 

The  arch  ring  is  finely  accentuated,  but,  unfortunately,  the  tailing  of  the 
ring  stones  does  not  match  with  the  courses  in  the  spandrels.  The  piers, 
spandrels  and  parapets  have  a  batter  of  1  in  48,  the  width  across  on  top  of 
die  parapets  being  21  feet.  The  length  of  the  piers  is  greater  than  the 
width  of  the  arches,  and  counterforts  are  carried  up  with  good  effect.  The 
belt  course  directly  above  the  voussoirs  is  in  entire  harmony  with  the  cor¬ 
nice  above,  which  is  formed  by  ornamental  corbels  supporting  the  coping, 
thus  making  a  portion  of  the  footways  on  each  side. 

The  footways  are  protected  by  iron  railings  of  light  design,  which,  how¬ 
ever,  appear  well,  owing  to  the  great  depth  of  masonry  above  the  extrados. 
The  difference  in  the  height  of  the  springing  of  the  50  feet  spans  and  the  80 
feet  spans  is  taken  care  of  in  a  very  appropriate  manner  by  the  two  coping- 
courses  on  the  piers  which  are  common  to  both. 

The  water  tower  of  elegant  design  adds  much  to  the  architectural  ef¬ 
fect,  which  is  not  much  marred  by  the  well-designed  stack.  While  many 
European  structures  are  more  expensive  and  more  elaborate,  High  Bridge 
compares  favorably  with  them,  and  will  remain  for  scores  of  years,  a 
credit  not  alone  to  the  engineer  who  conceived  it,  but  to  the  City  of  New 
York  as  well. 


14 


Engineering  News 


BRIDGE  BOOKS. 

GREENE,  Prof.  CHAS.  E.,  “Structural  Mechanics.”  Cloth,  G  x  9  ins. ;  271  pp.  $3.00 
HALL,  JOHN  L.,  “Tables  of  Squares.”  Containing  the  True  Square  of  every 
foot,  inch  and  one-sixteenth  of  an  inch  between  one-sixteenth  of  an 

inch  and  100  ft.  Flexible  morocco,  3%  x  5%  ins.;  gilt  edges .  2.00 

JOHNSON,  Prof.  J.  B.,  “Engineering  Contracts  and  Specifications;”  includ¬ 
ing  a  Synopsis  of  the  Law  of  Contracts  and  Examples  of  Various  En¬ 
gineering  Specifications.  New  edition,  containing  additional  specifica¬ 
tions  for  electric  railway  work . . . . .  3.00 

OSBORN,  FRANK  C.,  “Tables  of  Moments  of  Inertia  and  Squares  of  Radii 

of  Gyrations.”  Flexible  leather,  4  x  6%  ins.;  175  pp .  3.00 

WRIGHT,  C.H.,  and  WING,  Prof.  C.  B.,  “Manual  of  Bridge  Drafting.”  Flexi¬ 
ble  canvas,  9%  x  12  ins.;  214  pp.  and  24  pp.  tables;  50  pp.  plates  and 
6  full-size  blue  prints  from  actual  working  drawings  .  4.00 

SPECIFICATIONS. 

BOUSCAREN,  G.,  “Specifications  for  Railway  Bridges  and  Viaducts  of  Iron 

and  Steel.”  Paper,  8  x  13  ins. ;  9  pp . 25 

COOPER,  THEODORE,  “American  Railrpad  Bridges.”  Cloth,  7  X  9%  ins.; 


“Specifications, for  Steel  Highway  Bridges.”  (1890.)  Paper,  7  x  9%  ins.; 

25  pp . 25 

“Specifications  for  Steel  Railroad  Bridges.”  (1896.)  Paper,  7  x  9%  Ins.;- 


FOWLER,  CHAS.  E.,  “General  Specifications  for  Steel  Roofs  and  Build¬ 
ings.”  Paper,  6x9  ins.;  12  pp . 25 

OSBORN  GO.,  “General  Specifications  for  Railway  Bridges.”  Paper,  8  x  12  ins.; 

10  pp . . . . 25 

“General  Specifications  for  Bridge  Substructure.”  8  x  12  ins.;  10  pp . 25 

"Specifications  for  Metal  Highway  Bridge  Superstructure.”  8x  12  ins.; 

12  pp . . . . . 25 

STO WE'LL,  CHAS.  F.,  and  CUNNINGHAM,  A.  C.,  “General  Specifications  for 

Structural  Steel.”  Pap6r,  8%  x  1314  ins.;  11  pp . 25 

SWAAB,  S.  M.,  “Tables  and  Diagrams  for  Making  Estimates  for  Sewerage 

Work.”  Paper,  oblong,  414  x  7%  ins.;  20  pp.;  16  plates . 50 

THACHBR,  EDWIN,  “General  Specifications  for  Highway  Bridges.”  Pa¬ 
per,  8  x  13%  ins.;  8  pp . . 25 

“General  Specifications  for  Railway  Bridges.”  Paper,  8  X  13%  ins.;  8  pp. .  .25 

THOMSON,  G.  W.,  “Standard  Specifications  for  Structural  Steel  for  Modern 

Railroad  Bridges”  . . . 10 

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